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  • MediaSPIP 0.1 Beta version

    25 avril 2011, par

    MediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
    The zip file provided here only contains the sources of MediaSPIP in its standalone version.
    To get a working installation, you must manually install all-software dependencies on the server.
    If you want to use this archive for an installation in "farm mode", you will also need to proceed to other manual (...)

  • Multilang : améliorer l’interface pour les blocs multilingues

    18 février 2011, par

    Multilang est un plugin supplémentaire qui n’est pas activé par défaut lors de l’initialisation de MediaSPIP.
    Après son activation, une préconfiguration est mise en place automatiquement par MediaSPIP init permettant à la nouvelle fonctionnalité d’être automatiquement opérationnelle. Il n’est donc pas obligatoire de passer par une étape de configuration pour cela.

  • HTML5 audio and video support

    13 avril 2011, par

    MediaSPIP uses HTML5 video and audio tags to play multimedia files, taking advantage of the latest W3C innovations supported by modern browsers.
    The MediaSPIP player used has been created specifically for MediaSPIP and can be easily adapted to fit in with a specific theme.
    For older browsers the Flowplayer flash fallback is used.
    MediaSPIP allows for media playback on major mobile platforms with the above (...)

Sur d’autres sites (8166)

  • What does Elementary Stream mean in Terms of H264

    5 août 2015, par user1767754

    I read what an Elementary Stream is on Wikipedia. A tool i am using "Live555" is demanding "H.264 Video Elementary Stream File". So when exporting a Video from a Video Application, do i have to choose specific preferences to generate a "Elementery Stream" ?

  • Two pass high quality theora/vorbis ffmpeg encoding

    25 septembre 2017, par Lea Chescotta

    I want to achieve the same video encoding that I had with ffmpeg2theora with standard ffmpeg, this is because i need the flexibility ffmpeg has to make the container mkv, with subtitles other than srt.

    In ffmpeg2theora i have the following command that output a very high quality and very small filesize file :

    $ ffmpeg2theora --videobitrate 2000 --two-pass --first-pass firstpass --speedlevel 0 --width 640 --height 360 --resize-method lanczos --noaudio input.mkv
    $ ffmpeg2theora --videobitrate 2000 --two-pass --second-pass firstpass --speedlevel 0 --width 640 --height 360 --resize-method lanczos --noaudio input.mkv --output output.ogv

    Being the most interesting options here i think (From ffmpeg2theora manual page) :

    --two-pass
    --first-pass <filename>
    --second-pass <filename>
    --speedlevel
       encoding is faster with higher values the cost is quality and bandwidth (default 1)
    </filename></filename>

    But i can only found a simple way to encode theora/vorbis in standard ffmpeg (from : https://trac.ffmpeg.org/wiki/TheoraVorbisEncodingGuide) :

    ffmpeg -i input.mkv -codec:v libtheora -qscale:v 7 -codec:a libvorbis -qscale:a 5 output.ogv

    That produces a very bad quality output even in the best quality setting (10)

    How can I do a 2 pass ’high quality’/’not so big filesize’ theora/vorbis in plain ffmpeg ?

  • FFMPEG Seeking with concat demuxer causes video & audio to be out of sync

    20 février 2023, par Garuuk

    I have a very simple use case that's driving me bananas.

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    My problem and question :

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    I'm using ffmpeg version 5.1.2 on a MacOS and i'm using ffmpeg seeking and concat demuxer to cut many 1 minute videos into 15 seconds chopped up over 12 clips where every clip is just 2 seconds from the same video (kind of like a mini teasers for the video). I would really like to not have to re-encode to make the video processing as fast as possible.

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    First, I take each 1 minute video and cut it up into 12 clips (I do all this programmatically in python fwiw)

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    ffmpeg -ss 0 -i input.mp4 -t 2 -c copy -y cut_1.mp4&#xA;ffmpeg -ss 4 -i input.mp4 -t 2 -c copy -y cut_2.mp4&#xA;ffmpeg -ss 8 -i input.mp4 -t 2 -c copy -y cut_3.mp4&#xA;...&#xA;...&#xA;

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    I then write all the output file names to my concat_manifest.txt

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    file cut_1.mp4&#xA;file cut_2.mp4&#xA;...&#xA;...&#xA;

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    Then I run my concat command :

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    ffmpeg -f concat -i concat_manifest.txt -c copy -y concat_video.mp4&#xA;

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    This works really fast but the audio and video at the stitch point get out of sync and sometimes the video just chokes & lags. It's mostly not a smooth experience.

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    What I have tried :

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    1. using the concat protocol with intermediate profiles : ffmpeg.org/wiki/Concatenate#demuxer
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    3. Putting the -ss when I seek after the -i. This makes everything worse
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    5. Playing around with different -ss values. This has some noticeable affects but it's not obvious why yet.
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    7. I've also read from the ffmpeg resource regarding seeking and copying :
    8. &#xA;

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    Which leads me to believe that maybe because ffmpeg is using timestamps instead of frames, seeking isn't accurate using -ss when using the concat demuxer

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    Is there a way to get concat demuxer cutting and concatenating the video where the audio is somewhat in sync with the video ?

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    Thanks

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    EDIT : I found an answer and i'll be posting the solution in the coming few days.

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